1. Field of the Invention
The present invention relates to curculin B and a DNA encoding the same, and a process for production thereof.
2. Description of the Related Art
Curculigo latifolia is a plant belonging to Hypoxidaceae (or Amaryllidaceae according to a different method of classification) and grows naturally in Western Malaysia, the southern part of Thailand, etc. Curculin homologue (hereinafter referred to as curculin), the protein contained in Curculigo latifolia, has been recognized by the inventors of the present invention in the past as being useful as a taste-modifier. Further, the inventors described curculin obtained from Curculigo latifolia in Japanese Unexamined Published Patent Application (Kokai) No. 2-104263 and disclosed a method of stabilization of curculin in Japanese Unexamined Published Patent Application (Kokai) No. 2-84157 and methods of processing curculin in Japanese Unexamined Published Patent Application (Kokai) No. 2-84160 and Japanese Unexamined Published Patent Application (Kokai) No. 2-84161. Further, the complete amino acid sequence of a curculin (hereinafter referred to as curculin A) in curculin homologue is described in Japanese Unexamined Published Patent Application (Kokai) No. 3-190899.
However, in the techniques described in said Japanese Unexamined Published Patent Applications (Kokai) No. 2-104263, No. 2-84157, No. 2-84160, No. 2-84161 and No. 3-190899, the curculin was extracted from the Curculigo lacifolia plant, and so mass production was difficult. Further, there were the problems that the Curculigo latifolia plant is not easily handled, and further the activity of the curculin obtained by the extraction method is likely to be lowered.